Many buildings and structures use a central forced air system for heating and/or cooling the building or structure. Many buildings and structures further control the climate therewithin by controlling the humidity as well. Proper humidity has been found necessary for health reasons as well as for comfort reasons and to protect equipment located within the building or structure.
Therefore, the art contains several different designs for humidifiers that can be used in conjunction with a forced air heating system. These designs include: humidifiers that use heating elements such as film boilers, electric heaters and steam tubes that heat water and generate steam which is injected into the furnace; humidifiers that include a spray nozzle in which water is vaporized by nozzle action and injected into the hot air plenum of a furnace; evaporative type humidifiers which include a drum covered with an evaporative pad that revolves into a position for air to be blown across the water-saturated pad and into a furnace plenum; humidifiers using an impeller that sprays a mist of water into the hot air plenum of a furnace; and humidifiers which include a wick inserted into a source of water and has air blown across the saturated portion of the wick and into the forced air system.
Each of these humidifiers has one or more drawbacks, including: reliability, energy-efficiency, and susceptibility to clogging due to minerals in the water. Furthermore, some of these humidifiers may even be subject to problems associated with bacteria, and may be difficult to service and replace parts, thereby increasing the overall cost of the unit. Some of these units may also be difficult to attach to a furnace, and may even cause rust and corrosion. Still further, some of these humidifiers require lime, and cannot be easily drained, and may not have automatic shutoff features in the event that some portion thereof is not operating at a desired efficiency. Still further, "white dust" may create a problem for many of these humidifiers. Heating elements may have limited life expectancy, and moving parts also may have limited life expectancy, both further exacerbating the maintenance costs of any such humidifier. Many of the known humidifiers also cannot be accurately controlled, and cannot be used at all in a cooling situation.
Still further, for various reasons, all of these humidifiers require a downstream connection to a hot air plenum or a hot air portion of the forced air system. Such a requirement creates additional drawbacks and limitations.
Of the humidifiers known to the inventor, none can be used in conjunction with an air cooling, or air conditioning, central forced air system.
Therefore, there is a need for a humidifier that does not need to be connected to a hot air portion of a central forced air system, and can operate when connected to a cold air portion of such a system. Still further, there is a need for a humidifier that can be used in conjunction with a central forced air cooling system.